A need exists, with increased interest in backpacking, fishing and hunting, for a compact, versatile, safe and reasonably priced pistol for rimfire cartridges. There is also a need for an effective adaptor or insert for large bore center fire weapons that will allow rimfire cartridges to be fired from the larger bore weapons. An ideal solution to these related problems is found in the present invention.
A pistol and a small bore insert for large bore weapons may both be provided through the present invention.
The pistol configuration is adapted to use the small bore insert as a barrel. The insert can be selectively removed from the pistol body and loaded into the firing chamber of a larger bore weapon, thereby enabling the large bore weapon to fire a small bore cartridge.
Inserts or adaptors have been developed that allow firing of small bore, "rimfire" cartridges from larger bore "center-fire" weapons. They are generally made of soft metal (such as aluminum) since the expansive forces of cartridges fired within the insert are accommodated by the firing chamber of the larger bore weapon. Without the strength of the heavy, large bore firing chamber, the small bore inserts would at best have a rather short life and conceivably could explode.
Prior forms of inserts are also unsafe to carry in a "loaded" condition with the small bore cartridge in place. Prior inserts typically include their own firing pin that may be struck by a center fire firing pin and, in turn, strikes the "rim" of the small bore cartridge. The insert firing pin is typically mounted with its rimfire end in direct abutment with the small bore cartridge rim. It takes much less striking force to fire a rimfire cartridge than it does a larger bore center-fire cartridge. Therefore, there is always potential danger that a loaded insert could fire if dropped or otherwise handled carelessly. Other inserts that allow for axial travel of the insert firing pin are just as dangerous because there is no provision to yieldably hold the firing pin back away from the small bore cartridge rim.
U.S. Pat. No. 3,050,894 illustrates in FIGS. 13 through 16, a barrel insert that allows a center fire weapon to fire a rimfire cartridge. The insert includes a firing pin mechanism that slides freely in the cartridge to engage the rim of a rimfire cartridge. Another U.S. Pat. No. 3,598,053 shows a similar arrangement, only with the rimfire end of the firing pin having two pin branches, both for striking a rimfire cartridge.